lm5008asdcx National Semiconductor Corporation, lm5008asdcx Datasheet - Page 2

• Manufacturer Part Number: lm5008asdcx
• Description: 100v, 350 Ma Constant On-time Buck Switching Regulator
• Manufacturer: National Semiconductor Corporation

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Pin
1
2
3
4
5
6
7
8
Connection Diagrams
Ordering Information
Pin Descriptions
RT/SD
Name
RCL
RTN
VCC
BST
SW
VIN
EP
FB
LM5008ASDCX
Order Number
LM5008AMMX
LM5008ASDC
LM5008AMM
Switching Node
Boost Pin (Boot–strap capacitor
input)
Current Limit OFF time set pin
Ground pin
Feedback input from Regulated
Output
On time set pin
Output from the internal high voltage
series pass regulator.
Input voltage
Exposed Pad
8-Lead LLP
Top View
Description
Package Type
MSOP-8
LLP-8
30074902
Power switching node. Connect to the output inductor, re-circulating diode, and
bootstrap capacitor.
An external capacitor is required between the BST and the SW pins. A 0.01
µF ceramic capacitor is recommended. An internal diode charges the capacitor
from V
A resistor between this pin and RTN sets the off-time when current limit is
detected. The off-time is preset to 35 µs if FB = 0V.
Ground for the entire circuit.
This pin is connected to the inverting input of the internal regulation
comparator. The regulation threshold is 2.5V.
A resistor between this pin and VIN sets the switch on time as a function of
V
voltage. This pin can be used for remote shutdown.
This regulated voltage provides gate drive power for the internal Buck switch.
An internal diode is provided between this pin and the BST pin. A local 0.47
µF decoupling capacitor is required. The series pass regulator is current limited
to 9 mA.
Input operating range: 6V to 95V.
The exposed pad has no electrical contact. Connect to system ground plane
for reduced thermal resistance.
IN
. The minimum recommended on time is 400 ns at the maximum input
CC
during each off-time.
2
NSC Package Drawing
MUA08A
SDC08B
Application Information
8-Lead MSOP
Top View
1000 Units on Tape and Reel
3500 Units on Tape and Reel
1000 Units on Tape and Reel
4500 Units on Tape and Reel
Supplied As
30074903